Re: gnumeric to Haskell

[Jody Goldberg <jody gnome org>]

On Fri, Oct 24, 2003 at 05:06:48PM +1000, Lloyd wrote:
> I have some machine-learning code, written in Haskell,
> that I would like to be able to call from gnumeric.
>
> Haskell (ghc) has a nice foreign function interface (FFI),
> i.e. Haskell <-> C, that is quite easy to start using.
>
> I have looked at some gnumeric documentation, such as the
> simple `add two numbers' example function, but don't know
> exactly where and how one would actually add this example
> to gnumeric.
>
> So I have a considerable gap, on the gnumeric side,
> in the necessary knowledge to get started on this.
> Probably the way to proceed will be to
> write some C<->Haskell to understand gnumeric
> values, cells, sheets, ?ranges? which should
> be easy (well, less hard). The present difficulty
> is how and where to add or "register" this stuff
> ( .../plugins/fn-date/ is rather daunting and seems
>   a long way from `add two numbers').

The process should be fairly simple, but will depend a bit on
exactly what you'd like to do.

1) Write a general purpose bridge to haskel so that you can write
arbitrary sheet functions in haskel and have them available in a
workbook.  Look at something like the guile plugin to see how this
works.

2) write a function in C that internally uses some haskel code.
This is obviously much simpler.